National Forest Research Articles

Species Richness and Similarity of New Zealand Mayfly Communities (Ephemeroptera) Decline with Increasing Latitude and Altitude.

The distribution of species in relation to latitude and altitude is of fundamental interest to ecologists and is expected to attain increasing importance as the Earth's climate continues to change. Species diversity is commonly greater at lower than higher latitudes on a global scale, and the similarity of communities frequently decreases with distance. Nevertheless, reasons for such patterns are not well understood. We investigated species richness and changes in community composition of mayflies (Ephemeroptera) over 13 degrees of latitude at 81 locations throughout New Zealand by light-trapping and the benthic sampling of streams. Mayflies were also sampled along an altitudinal gradient on a prominent inactive volcano in the east of North Island. Sampled streams were predominantly in the native forest, at a wide range of altitudes from sea level to c. 1000 m a. s. l. A total of 47 of the 59 described New Zealand mayflies were recorded during the study, along with five undescribed morphospecies. Species richness declined and the degree of dissimilarity (beta diversity) of mayfly communities increased significantly from north to south but less strongly with increasing altitude. Our results suggest that the southward decline in species richness has historical origins with the north of the country having acted as a major refuge and region of speciation during the Pleistocene. The increasing dissimilarity of the northern and southern communities may reflect an increasingly harsh climate, variable amounts of subsequent southward dispersal of northern species and, in the South Island, the presence of species which may have evolved in the newly uplifted mountains during the Miocene-Pliocene.

The Impact of Tourists’ Perceived Value on Environmentally Responsible Behavior in an Urban Forest Park: The Mediating Effects of Satisfaction and Subjective Well-Being

Urban forest parks serve as significant venues for tourists’ leisure and recreation. The experiences and perceptions of tourists in these parks considerably influence their attitudes and behaviors. While numerous studies have investigated the functions and values of urban forest parks at a macro level, the mechanisms influencing tourists’ perceived values and their environmentally responsible behavior at a micro level remain under explored. This research used structural equation modeling (SEM) to test the association between tourists’ perceived values and their environmentally responsible behavior, including the mediating functions of tourists’ satisfaction and their subjective well-being. 502 valid questionnaires in total were obtained from Changpoling National Forest Park in Guiyang City, Guizhou, China, for this case study. The results show that there are some variances in the impact of the dimensions of tourists’ perceived value on environmentally responsible behavior, in which service quality, resource quality, and emotional value impose a pronounced positive effect on environmentally responsible behavior, tourism costs impose a pronounced negative effect on environmentally responsible behavior, and the activity experience does not exert a pronounced effect on environmentally responsible behavior. Satisfaction and subjective well-being have a mediating function during the process of positive influence of tourists’ perceived value on their environmentally responsible behavior and serve as partial mediators, and the significant positive influence of satisfaction on subjective well-being as well as subjective well-being on environmentally responsible behavior are verified. This research can help better explain the mechanism of the effect of tourists’ perceived value exerted on environmental responsibility behavior in nature-based tourism destinations, and also has a guiding and reference significance for the sustainable development of urban forest parks.

Timber Harvest Planning Using Reinforcement Learning: A Feasibility Study

This study developed a forest management plan model using reinforcement learning (Q-learning) to optimize both the economic and ecological functions of forests. Management objectives for national forests were established, and forest conditions were analyzed using GIS spatial data and administrative records. A 60-year forest management plan was formulated to predict timber production and management performance across different regions and time periods. Our analysis revealed that Scenario 3 (Carbon Storage Priority) demonstrated the highest economic value, starting at approximately KRW 576.2 billion in the initial period and escalating to KRW 775.7 billion over six 10-year periods, totaling 60 years. In addition to its economic performance, Scenario 3 effectively improved forest age class structure and ensured a stable timber supply, making it the most balanced approach for sustainable forest management. By focusing on carbon storage as a key management goal, this approach highlights the potential for achieving both economic and environmental benefits concurrently. These results suggest that reinforcement learning is a powerful tool for developing long-term forest management strategies that address multiple objectives, including economic viability, ecological sustainability, and resource optimization.

Predicting the drivers of Bothrops snakebite incidence across Brazil: A Spatial Analysis

Snakebite envenoming poses a significant public health challenge on a global basis, affecting millions of people annually and leading to complications that may result in fatalities. Brazil stands as one of the countries most impacted by snakebite envenoming, with snakes of the Bothrops genus being responsible for most bites. The current study aimed to identify the determinants of Bothrops snakebite incidence across different regions of Brazil. An ecological study was conducted using municipality-aggregated data, with snakebite incidence as the dependent variable. The study period comprised the years 2015–2021. We constructed Species Distribution Models (SDMs) for Bothrops species, and information was collected on precipitation, runoff, maximum and minimum temperatures, native forest, historical forest loss, agriculture, and pasture in each Brazilian municipality. These data were employed to assess the association between snakebite incidence and biotic, climatic, and landscape factors. The data were analyzed using Generalized Least Squares (GLS) regression. The SDMs demonstrated good performance. The average annual snakebite incidence during the study period ranged from zero to 428.89 per 100,000 inhabitants, depending on the municipality. Higher incidence rates were concentrated primarily in municipalities in the northern region of the country. In this study, we found that nationwide, areas with extensive native forests and those that have historically experienced significant loss of forest cover exhibited higher snakebite incidence rates. Additionally, areas with higher temperatures and precipitation levels, as well as greater climatic suitability for the species B. jararaca, showed significantly higher snakebite incidence rates in the South and Southeast of Brazil, respectively. These associations may be linked to increased snake abundance and active behavior, as well as to engagement in activities favoring human-snake contact in these areas. The findings of this study can contribute to the improvement of prevention and control strategies for this public health issue in Brazil.

Ghost species form an important component of the epiphytic lichens in temperate forests

Sequencing of environmental samples has great potential for biodiversity research, but its application is limited by the lack of reliable DNA barcode databases for species identifications. Such a database has been created for epiphytic lichens of Europe, allowing us to compare the results of environmental sequencing with standard taxonomic surveys. The species undetected by taxonomic surveys (what we term the ghost component) amount to about half of the species actually present in hectare plots of Central European forests. Some of these, which currently occur only as diaspores or weakly developed thalli, are likely to be favoured in the course of global change. The ghost component usually represents a larger fraction in managed forests than in old-growth unmanaged forests. The total species composition of different plots is much more similar than suggested by taxonomic surveys alone. On a regional scale, this supports the well-known statement that “everything is everywhere, but, the environment selects”.

Nitrogen deposition contributed to a global increase in nitrous oxide emissions from forest soils

Nitrous oxide is a potent greenhouse gas. Anthropogenically enhanced nitrogen deposition causes natural forest soils to release more nitrous oxide, exacerbating global warming. We used data from nitrogen addition experiments conducted in forests worldwide to quantify the spatially varying sensitivity of soil nitrous oxide emission to nitrogen deposition, thereby inferring soil nitrous oxide emission dynamics from nitrogen deposition data. From 1985 to 2015, nitrous oxide emitted from global forest soils increased from 3.55 to 3.85 teragrams of nitrogen per year. Nitrogen deposition contributed directly to 9.0% of global forest soil nitrous oxide emissions. The derived country-specific sensitivities of soil nitrous oxide emission to nitrogen deposition could be employed as localized emission factors for forestland nitrous oxide emission inventories. This study sheds light on a process-augmented data-driven approach to estimating global nitrous oxide emissions by synthesizing experimental and observational data.

Planted Forests Greened 7% Slower Than Natural Forests in Southern China Over the Past Forty Years

AbstractForests have seen a strong greening trend worldwide, and previous studies have attributed this mainly to land‐use conversions such as afforestation. However, for the greening of existing forests, the role of human interventions is unclear. Here we paired neighboring natural and planted forests in Southern China to minimize the differences between the forest types and analyzed the vegetation index EVI2 from Landsat over 1987 to 2021. The EVI2 trends observed in natural forests can be seen as mainly responses to large‐scale environmental changes, whereas the difference between the forest types represents the impact caused by human interventions. We found that though the mean EVI2 of planted forests was comparable to that of natural forests, the greening trends were overall 7.0% lower in planted forests. Our results suggest that human interventions associated with planted forests did not accelerate their greening, indicating the necessity for refined policies to enhance future forest greening.

Assessing the role of natural kelp forests in modifying seawater chemistry

Climate change is causing widespread impacts on seawater pH through ocean acidification (OA). Kelp forests, in some locations can buffer the effects of OA through photosynthesis. However, the factors influencing this variation remain poorly understood. To address this gap, we conducted a literature review and field deployments of pH and dissolved oxygen (DO) loggers within four habitats: intact kelp forest, moderate kelp cover, sparse kelp cover and barrens at one site in Port Phillip Bay, a wind-wave dominated coastal embayment in Victoria, Australia. Additionally, a wave logger was placed directly in front of the intact kelp forest and barrens habitats. Most studies reported that kelp increased seawater pH and DO during the day, compared to controls without kelp. This effect was more pronounced in densely populated forests, particularly in shallow, sheltered conditions. Our field study was broadly consistent with these observations, with intact kelp habitat having higher seawater pH than habitats with less kelp or barrens and higher seawater DO compared to barrens, particularly in the afternoon and during calmer wave conditions. Although kelp forests can provide local refuges to biota from OA, the benefits are variable through time and may be reduced by declines in kelp density and increased wave exposure.

Historical pyrodiversity in Douglas-fir forests of the southern Cascades of Oregon, USA

Our understanding of forest dynamics and successional pathways in coastal Douglas-fir (Pseudotsuga menziesii var menziesii) forests with relatively frequent mixed-severity fires is limited by a lack of annually precise dendroecological reconstructions that combine records of historical fires and tree establishment. The processes by which old-forest heterogeneity developed under historical fire regimes with recurrent low- and moderate-severity fires has not been well studied at fine temporal scales and across spatial scales. We developed crossdated multi-century records of fire and tree establishment histories in old forests (170 – 550 years) at 34 plots distributed across six sites. Study sites include warm-dry to cool-moist Douglas-fir forest types found in the southern west Cascades of Oregon, USA. Spatial variability in historical fire frequency and fire effects resulted in tremendous diversity in forest developmental histories, age structure, and forest conditions. Most historical fire intervals were very frequent (<10 years) to frequent (<25 years) in dry Douglas-fir forests. Exceptionally high fire frequency and an abrupt decrease in fire frequency after European colonization in dry Douglas-fir forests adds to growing evidence and recognition of Indigenous fire stewardship in montane Douglas-fir forests. In moist forests where Douglas-fir is seral to western hemlock, fire intervals were frequent to moderately frequent (<50 years), but intervals varied substantially over time. Relatively young moist forests burned frequently while mature moist forests had long fire intervals (50–160 years). Nearly all tree establishment cohorts were preceded by either stand-replacing (28 %) or non-stand-replacing fires (64 %). However, tree cohorts only provided evidence of 16 % of historical fire events that we reconstructed from cambial fire scars. This study demonstrates that frequent fire can be an important driver of forest development and in some contexts shapes the structure of coastal old-growth Douglas-fir forests, which are often characterized as developing from endogenous disturbances during long fire-free periods. The high level of pyrodiversity we observed was associated with variation in and interactions of micro-climate, topography, fuels, and Indigenous fire stewardship. We recommend rigorous dendroecological reconstructions across the coastal Douglas-fir region to refine our understanding of the geography of fire-mediated forest developmental dynamics in this important forest type, to inform forest management, conservation, and ecocultural restoration.

How dominant height responds to mixing species: Effect of traits and height difference between species

Adapting forests to climate change is a major challenge for forest ecology and forestry. Among the management options available, encouraging the use of mixtures is a promising way forward. However, this practice requires a thorough understanding of how species respond to mixing. In this article, we analyzed species dominant height responds to mixing and how species ontogeny and traits drive this response. We compared species observed dominant height in mixed even-aged stands with the expected dominant height of the same species in a monospecific stand under the same environmental conditions. We then related this dominant height variation due to mixing to between-species dominant height difference and to species traits linked to competition (shade tolerance, wood density, specific leaf area).We focused our analyses on 76 pairs of forest tree species. We used data from the French National Forest Inventory to calculate species dominant height in 1368 mixed stands. We then used previously developed models to estimate the expected dominant height in virtual monospecific stands with the same environmental conditions.We found that mixture had a significant impact on species dominant height for 15 out of 50 species-combination considered. Dominant height of a given species was higher in mixture than in pure stands when this species had a lower dominant height in pure stands, a lower shade tolerance, a lower specific leaf area or a higher wood density than its companion species.Our results suggest that species dominant height response to mixing depends on how mixture influences the competition for light. Our results will help inform strategies aiming to diversify species in forests, and will be especially useful in anticipating a given species’ behavior in response to competition for light when it is mixed with other species.

Assessing the impact of urbanization on forest carbon stocks and social costs using a machine learning approach

Urbanization frequently precipitates urban sprawl, resulting in deforestation and alterations in landscape and land alterations. Such transformations profoundly impact the carbon stocks within metropolitan regions. This study examines the ramifications of urbanization on alterations in carbon stocks within urban forests across ten South Korean cities experiencing substantial urbanization over the past 15 years. Leveraging machine learning techniques and high-resolution satellite imagery, we scrutinize changes in land usage and urban forests, utilizing them to gauge the societal costs linked with shifts in urban carbon stocks. Furthermore, we integrate regional-level data sourced from national forests to enhance the precision of carbon stock estimations. Data analysis reveals that over the 15 years, urban areas expanded at an average rate of 4.43 km2 annually. In comparison, forested areas decreased by an average of −2.19 km2 per year, resulting in an average annual decline of −3171 tC in forest carbon stocks due to urbanization. The fluctuation in carbon stocks across the urban forests of the ten cities ranged from −68 % to 48 % over 15 years, primarily influenced by the extent of preserved forest area, with forest composition playing a secondary role. Concurrently, carbon sequestration efficiency varied between cities, ranging from 8 % to 57 % over 15 years, contingent upon tree type and forest age composition. An approximate loss of 174,380 tCO2eq of carbon stocks attributable to urbanization is estimated, with the associated social cost of increased emissions estimated at $8,893,396. Effective management of carbon emissions and sinks within urban locales is paramount for climate change mitigation, given the substantial contribution of urban areas to global carbon emissions. This study underscores the significance of urban forest management in carbon governance and furnishes valuable insights into nations undergoing rapid urban expansion.

Applying Reiss’ expectancy theory to locals’ perceptions of a potential red wolf reintroduction to Ozark National Forest, AR

ABSTRACT Although perceptions of risk related to wildlife have been well-studied, little research has evaluated the root causes of these perceived risks. Using a semi-structured instrument, we interviewed 20 interested parties who reside and/or recreate near Ozark National Forest, Arkansas, to explore perceptions of a potential red wolf (Canis rufus) reintroduction to the region. We employed Reiss’ (1991) expectancy theory to identify cause and effect relationships between previous conditioning events interested parties had experienced (i.e. sensitivities) and perceived risks related to the reintroduction (i.e. expectancies). We found respondents drew parallels to previous events including the red wolf reintroduction to North Carolina, other wildlife reintroductions in Arkansas, gray wolf (Canis lupus) reintroductions in Yellowstone National Park, and conflicts with other wildlife in Arkansas, where distrust for wildlife agencies underpinned these experiences. Based on our findings, we recommend agencies preemptively build trust and practice clear and frequent communication among interested parties when reintroductions are being considered.

Coordinated Development of Forests and Society: Insights and Lessons from Natural Forest Restoration and Regional Development in China

Coordinated Development of Forests and Society: Insights and Lessons from Natural Forest Restoration and Regional Development in China

Large-scale forest protection: the successful case of the Kayapo people in the Brazilian Amazon

Forest conservation is essential for action on climate change and biodiversity loss. Forest loss and degradation are increasing around the world, including in the Amazon. It is widely reported that Indigenous communities can be effective in forest protection, but less attention has been paid to explaining how they are able to do this in the face of severe threats. This article investigates what can be learned from the success of the Kayapo Indigenous communities and their organizations in protecting more than nine million hectares of primary forest in one of the most highly degraded and deforested areas of the Brazilian Amazon. We use geographic information system analysis to demonstrate the extent of forest protection, along with field work to examine the crucial alliances with conservation NGOs from governance and planning perspectives. Our interdisciplinary analysis is guided by the three-pillar framework for integrated landscape management and is informed by interviews conducted with Indigenous and non-Indigenous staff working for the Kayapo NGOs. Based on this data and the experience of the Kayapo people, we identify the main factors that facilitated large-scale forest conservation. Our research also reveals that the work of the Kayapo NGOs aligns with the principles of strong governance and effective planning. Lastly, we discuss key lessons and critical considerations to ensure the continued viability and ongoing success of the Kayapo NGOs in achieving their objectives.

Changes in plant resource inputs lead to rapid alterations in soil dissolved organic matter composition in an old-growth tropical forest

Alterations in plant resource inputs to soil affect soil organic matter (OM) dynamics. However, it remains unclear how to alter soil dissolved OM (DOM) composition. Here, we used UV/fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry to analyze soil DOM’s optical and molecular characteristics after eight months of detritus input and removal in an old-growth tropical forest. Changes in plant inputs significantly altered soil DOM’s optical properties, and the most pronounced changes were observed in the humification index and fluorescent components. In litterfall removal and no-input plots, molecular characteristic values increased greatly, such as O/C, double-bond equivalent, aromaticity index, and proportion of carboxyl-rich alicyclic molecules, while biolabile compounds decreased. The abundance of lignin-like and tannin-like compounds was more than 20 % higher in litter removal plots than in no-input plots. Our findings indicate that changes in plant resource inputs can lead to rapid alterations in soil DOM composition.

On the Conservation of the Canarian Laurel Forest: What Do Lichens Have to Say?

The fragmentation and degradation of primary forests are serious threats to the long-term persistence not only of the tree species they comprise, but also of many organisms inhabiting them. The Canarian laurel forest, known as monteverde, is a highly threatened endemic forest of the Macaronesian region. Lichens are considered ideal bioindicators for assessing the effects of human disturbances on ecosystems and anticipating the response of other less sensitive organisms. However, no studies have used them as model organisms to analyze the conservation status of this primary forest in the Macaronesian region. In the present study, we analyzed several variables of the lichen biota of the Canarian laurel forest on the islands with the highest representation within this archipelago: La Gomera, La Palma, and Tenerife. We analyzed the species richness (and its relationship to island size with the real and potential vegetation areas of the laurel forest); the lichen diversity value, the number of shared and exclusive species on each of the islands as well as lichen functional traits as they have become important for evaluating the response of epiphytic lichens to environmental changes. The results indicate that there are signs of a potential extinction debt occurring in the diversity of epiphytic lichens in some areas. Furthermore, it has been observed that, despite the presence of some exclusive species on each island, the overall composition does not differ between them. Considering the functional traits of lichens, there are patterns that can provide information about the unique characteristics of the laurel forest of each of the studied islands.

Land use transformations in the Brazilian Savanna: A decade of soil erosion and runoff measurements

Changes in land cover and land use (LULC) are one of the main drivers of erosion and runoff. How ever, most research has relied on short-term observations and only focused on one or two land cover types. We investigated the long-term trade-off between common agricultural land covers (sugarcane, pasture, and soybean), runoff, and soil loss rates. We compared these to native forest (wooded Cerrado) and bare soil. The field observations were done in 100 m2 experimental plots in Brazil maintained during the past 10 years. The paper provides three main contributions: (1) long-term runoff and soil loss rates of plots under different LULCs, (2) comparison of runoff, soil loss, and pedological characteristics between plots constructed 10 years apart, and (3) analysis of the trade-off between different LULCs. When ranking land covers based on runoff and soil loss rates, there is a shift in ranking positions, making it difficult to determine which one is more environmentally harmful. However, it is evident that whatever agricultural practice is used, there is a significant impact when compared to native forest. For example, the area converted to pasture resulted in almost 20 times higher runoff, while conversion to sugarcane resulted in 5 times higher soil loss. Not only land cover plays a major influencing factor, but also weathering exposing time. Areas under the same land cover and environmental conditions had different rates of soil loss and runoff due to long-term exposure effects such as soil crusting. Our findings have high relevance for the hydrological and agricultural community by demonstrating (i) the magnitude of trade-off in terms of soil loss and runoff due to land cover changes and (ii) that soil loss should not be assumed to be a linear process over time, as it is commonly assumed.

A mixed-effects height-diameter model for Pinus douglasiana Martínez in temperate forests of Jalisco, Mexico

predicting tree-height of Pinus douglasiana in the natural forests of Jalisco, Mexico. Design/methodology/approach: For this study, we utilized 2,921 pairs of tree-height measurements collected from 65 permanent plots (each 50x50 m) in the study area. For each plot, we estimated the tree density as the number of trees per hectare (N, ha-1), the basal area per hectare (G, m2 ha-1) and the quadratic mean diameter (dg, cm). Subsequently, we tested several models from the literature and developed a generalized mixed-effects model for tree height prediction. Results: The Gompertz base model outperformed the other local models, achieving an R² of 0.75 and an RMSE of 3.13. Including the stand variables (N, G, and dg) and incorporating random effects significantly improved the model fit, resulting in an R² of 0.89 and an RMSE of 2.09 m. Calibration and validation steps revealed that selecting the three thickest trees is effective for estimating random effects in new plots or stands, with the RMSE and R² being 2.59 and 0.83, respectively. Limitations on study/implications: The present model can be applied in areas where P. douglasiana is naturally distributed. However, it is advisable to calibrate the model using a sub-sample to achieve more accurate predictions of tree heights in new plots or areas. Findings/conclusions: The Gompertz function was used as the base function to develop the final generalized mixed-effects model for predicting the height of Pinus douglasiana. The inclusion of stand variables (N, G, and dg) along with random effects improved the model fit. This model represents a new and more accurate tool for predicting the height of P. douglasiana in areas where it is naturally distributed.

The Role of Spatial Morphology in Forest Landscape Fragmentation: Insights From Planted and Natural Forests of the Chinese Loess Plateau

ABSTRACTThis study aimed to emphasize the key role of spatial morphology of planted and natural forests on landscape fragmentation and to furnish a scientific foundation for the effective assessment of ecological restoration projects of vegetation on the Loess Plateau. The spatial morphological pattern and landscape fragmentation characteristics were analyzed using morphological spatial pattern analysis (MSPA) and forest area density methods. This is the inaugural study to reveal the linear and nonlinear relationships between forest landscape fragmentation and its driving factors using machine learning methods and introducing morphological indicators with two different strategies. The results showed significant differences in the spatial patterns and landscape fragmentation characteristics between planted and natural forests. The spatial patterns of planted and natural forests were found to be dominated by “Core” in terms of area, while “Branch” was more prevalent in terms of number. Compared to natural forests, planted forests were more fragmented. The introduction of the MSPA indicator significantly enhanced the explanatory power and predictive performance of the model despite the disparate contribution rates of the driving factors in planted and natural forests. This study highlights the importance of spatial morphology in understanding forest landscape fragmentation and provides a new combination of analytical techniques to better understand the complexity of forest ecosystems. These provide new insights into forest landscape restoration and sustainable management on the Loess Plateau.

Climate Profile Over Jeldu Woreda of West Shewa Zone, Oromia, Ethiopia

Identifying the climate profile of an area is essential for effective water resource management, agricultural planning and disaster preparedness. This study focuses on characterizing rainfall patterns and identifying the variability of Jeldu woreda in Oromia, Ethiopia. Previously and recently, little study tried to show the woreda profile, which did not bases on station data properly. Forty years (1981-2020) of stations’ rainfall and temperature data were utilized. The study area had natural forest, highland and mid land with varying topography. Based on the annual rainfall cycle, the woreda had bi-modal rainfall types, with the peak of the year being July. Statistical methods and python script were applied to identify the climate profile. The results show that main rainy seasonal rainfall starts on average from 12-14 June and ceases averagely around 10-15 October. During second rainy period, the rain starts from 25 February to 10 March. The mean annual rainfall of woreda is 1395.1 mm, and the average maximum temperature is 19.5°. Kiremt contributes the highest percent, which is more than 64 % of the annual total rainfall. The 1987 and 2015 were the driest years, and 1996 and 2010 is the wettest during kiremt, 1987 and 2010 the wettest, and 1999 and 2015 the driest during Belg. Seasonal rainfall had a regular to moderate precipitation concentration over woreda. Identifying the causes of unseasonal rainfall that happened during dry season over the study area can help to decrease weather hazard during the season.